Cloudera Docs

Delete ZNODES

Remove the ZNode for HDFS, YARN, Hive, HBase, and Oozie

If the cluster is configured for Namenode HA, the Failover controllers cannot determine the Active Namenode after the migration. This is because the naming conventions used to identify Namenodes for the HA service are different for Ambari and Cloudera Manager. You must format the ZooKeeper ZNode for the Failover controller to continue further.

If the cluster is configured for Yarn HA, the Resource Managers cannot elect an Active Resource Manager after the migration. You must clear the previous Znode from ZooKeeper so that YARN replaces it.

If the cluster is configured for Ranger KMS, you must delete the Ranger KMS Znode with superuser privileges. When you restart Ranger KMS, the znode gets created with correct privileges.

You must format the ZooKeeper Znode for the failover controller to continue further.

  1. Start ZooKeeper client CLI session from a master node. (Assuming that the skipACL is set to Yes to avoid authentication issues). zookeeper-client -server <zk_hostname>
  2. Remove the HDFS HA Failover controller Znode
    deleteall /hadoop-ha
  3. Remove the YARN ZNode
    deleteall /yarn-leader-election
  4. Remove the Hive ZNode
    deleteall /hive
    deleteall /hiveserver2
  5. Remove the HBase ZNode
    deleteall /hbase-secure
  6. Remove the Oozie ZNode
    deleteall /oozie
  7. Remove the Ranger KMS ZNode
    deleteall /zktsm